This paper analyzes the characteristics of Reactor Nuclear Measurement Systems,including Nuclear Instrumentation System(RPN),In-core Neutron Fluence Rate Measurement system(RIC),LOCA Surveillance System(LSS),and introduces the function distribution and interface design between the Nuclear Measurement Systems and the Digital Instrument Control System(DCS).Based on the advantages of DCS,3 different function distribution and interface design schemes are taken in Ling’ao Nuclear Power Station Phase Ⅱ for different function requirements and characteristics of RPN,RIC and LSS.Consequently,these design schemes lead to a good result in fault diagnosis and logic processing.